Polly B. Roly isn't like the other roly polies. She's a racer. And she's been training for today's race, the Over-the-hill and Leg-burner 10K. But all of the other racers are bigger and faster. Betty Bear. Honey Hamster. Bob Mole. Ollie Ostrich. A Who's Who of the racing world, and they're not afraid to make fun of her as they pass her on the way up the big hill. As a roly poly, Polly has a simple solution: curl up into a ball. But Polly has worked too hard for this. She has to keep going, no matter the physical toll or bullishness of her fellow racers. She can't roll into a ball and give up. It's time to rock 'n' unroll!